Computer-aided map navigation tools have achieved widespread acceptance. A user can find an address or directions with map navigation tools available at various Web sites. Some software programs allow a user to navigate over a map, zooming in towards the ground or zooming out away from the ground, or moving between different geographical positions. In cars, GPS devices have provided rudimentary road navigation for years. More recently, map navigation software for cellular telephones and other mobile computing devices has allowed users to zoom in, zoom out, and move around a map that shows details about geographical features, town, city, county and state locations, roads, and buildings.
Map navigation tools typically present metadata about map features as being “baked into” a flat, two-dimensional (“2D”) view of the map. For example, in a top-down map view, text labels are written over road details or image details at appropriate locations, and the text labels are effectively presented at the same ground level as the road or image details. This can cause excessive visual complexity due to the density of information that needs to be displayed at any given level of viewing the map.
To reduce the density of detail, many map navigation tools hide or reveal metadata depending on the view level of the map. For example, if the view is close to a small-scale feature such as a building, a text label about the feature is revealed, but the text label about the feature is hidden if the view is far from the small-scale feature. On the other hand, a text label about a large-scale feature such as a country or state is shown at a high-level view, but hidden at a view closer to ground level. At any given view level, however, the revealed text labels are still baked into a flat, 2D view of the map. And, the transitions between different view levels can be abrupt, as one 2D view is replaced with the next 2D view showing different metadata. As a result, the viewer can lose context during transitions and become disoriented.